Motivations for home energy retrofit

Energy retrofit is currently promoted with several schemes and incentives in the UK, such as the Green Deal, the Energy Company Obligation (ECO), the Feed in Tariff (FiT) and the Renewable Heat Incentive (RHI). Nevertheless, there is often mention of the barriers towards the wider implementation of energy retrofit in the domestic sector. In periods of financial uncertainty and difficulty, economic aspects are a priority for most homeowners and high capital cost is a considerable barrier towards energy retrofit.

Households are generally more risk adverse compared to companies for a variety of reasons; thus, spending a significant amount of their budget for retrofit is something that can be more easily said than done. To give an idea of the cost, the Energy Saving Trust estimates the cost of external wall insulation to range from £9,000 to £26,000 and that of internal wall insulation to be in the area of £4,000 to £16,000. Therefore, home owners might be concerned about the period of time they will live in a certain accommodation and if their investment will actually increase the property value. The actual energy savings and the payback time are highly considered as energy retrofit measures can have significantly long payback times, whether it is fabric or heating upgrades and energy savings, or installation of renewables and energy generation. Therefore, on a domestic level, homeowners hesitate to uptake energy efficient retrofit measures.

Energy savings are typically presented as the main benefit accruing from the installation of energy efficient measures. However, this alone is not necessarily an adequate motivation for home owners to proceed to the often costly implementation of energy efficient measures. Therefore, it is worth identifying and promoting other types of benefits, not necessarily related to the economic aspects of energy efficiency.

Research adds several benefits to the list of positive outcomes resulting from energy efficient retrofits of domestic properties. These can be noise reduction and improved acoustic conditions, enhanced appearance of houses, better control of bills and health benefits for the occupants.

One of the most significant co-benefits of energy efficient retrofit is related to thermal comfort. The UK Government this year has used the slogan ‘Keep warm this winter’ as a way to improve warmth for UK households, but also to potentially come closer to achieving the country’s carbon reduction targets. Interestingly, a domestic energy retrofit project in China, called ‘Warm Houses’ was very successful and served the national targets, while significantly improving the thermal comfort conditions of numerous people.

In terms of occupants’ health, energy retrofit can have a very significant impact on respiratory and circulatory conditions as well as on learning ability and productivity. Retrofit measures involving insulation, heating and cooling systems’ upgrades, increased access to ventilation and daylight can have a very positive effect on occupants’ health, especially as respiratory and circulation illnesses are particularly responsive to the effects of temperature. On the contrary, cold houses are more likely to increase humidity, which can lead to the growth of mould, and potentially subsequent respiratory symptoms.

On a different perspective, energy efficient retrofit are often accompanied by façade interventions, changing the external appearance of homes. This can function both as a barrier and as a benefit, depending on the scale and type of changes. Research in the UK has shown that owners do not like their houses to stand out, so retrofitting external insulation can sometimes be a challenge. In most cases, this process does not require a planning permission, unless dwellings are located in conservation areas, or are themselves listed properties, which significantly limits their options. On the positive side, the change of a façade can also be very significant, as it can enhance a building’s aesthetics, highly valued by home owners, and increases the property’s value. Finally, the wider community is more likely to take up similar measures, once one or few installations are successful and deliver results.

Timing for energy retrofit of domestic properties can be crucial and even bring up additional benefits, related to further refurbishment or maintenance works and repairs. For example, the installation of external wall insulation can be organised at a time when external facades might need painting or cladding, or when there are maintenance works on roofs and gutters. Similarly, internal wall insulation installation, which can be quite disruptive for the house occupants, should be scheduled when painting rooms or in cases of bathroom and/or kitchen refurbishments. This saves on maintenance costs and takes advantage of the high capital cost for energy retrofit to benefit on other housing improvements.

It is interesting to observe how different communities and cultures perceive domestic energy retrofit and how opportunities for its implementation vary between different countries. For example, there are countries where energy retrofit is primarily done in order to improve the property’s value, as in the case of Austria and Germany; in those countries, buildings’ energy efficiency is typically more highly valued. On the other hand, in countries like Finland, thermal comfort appears to be a more significant driver leading the carbon reduction of domestic properties.

This article has focused on the perspective of home owners towards domestic energy retrofit and on relevant co- benefits. There are of course significant co-benefits of energy retrofit, other than financial and energy savings, which can be identified on community and national level; these include but are not limited to the enhanced local air quality, the improved local economy and finally the achievement of national carbon reduction targets.

Image credit courtesy of Wikimedia Commons from Jennifer Dickert depicting a home in NH, USA being insulated.

Eleni Soulti is a researcher at the Centre for Sustainable Development of the University of Cambridge Department of Engineering. Her work deals with the Evaluation of Energy Efficient Technologies, focusing on solid wall insulation and the in-situ performance of insulation products. The aims of the research include assessing the gap between the estimated and the actual energy savings occurring due to the implementation of energy efficient technologies.